Purpose: VECF-C, -D and their receptor Flt-4 are associated with lymph node metastasis and a poor prognosis in many tumour entities. We have analysed the expression of these factors in transitional cell carcinoma of the bladder with positive lymph nodes.
Materials and methods: We constructed "tissue microarrays" (TMAs) from bladder cancer specimens (BC-array) and corresponding lymph node metastases (LN-array) of 73 patients, who all underwent radical cystectomy and bilateral lymphadenectomy. After immunohistochemical staining, semiquantitative analysis was performed using polyclonal antibodies for VEGF-C, -D and Flt-4. The results were correlated with various histopathological and clinical variables.
Results: VEGF-C (p = 0.007) and Flt-4 (p = 0.019) were significantly higher expressed in the LN-array compared to the BC-array. In the LN-array VEGF-D correlated with T-(p = 0.013) and N-stage (p = 0.030) Flt-4 correlated with N-stage (p = 0.011) and distant metastasis (p = 0.011) in the BC-array, as well as with T-(p = 0.004) and N-stage (p = 0.014) in the LN-array. Accordingly, in the LN-array VEGF-D positive patients showed both a shorter disease-free survival (p = 0.028) and a poorer overall survival (p = 0.014). Similarly, Flt-4 positive patients had a shorter overall survival (p = 0.033).
Conclusions: Patients with transitional bladder cancer and lymph node metastasis have a poorer prognosis when they overexpress VEGF-D and Flt-4 in their lymph nodes. Pharmacological targeting of these factors could improve their overall survival.